Significant technological advances in the design and production of electronic assemblies have sizably increased their reliability and durability while greatly reducing their physical size. New manufacturing technologies have been developed which markedly increase the speed and accuracy of production. Such advances in production greatly complicate the inspection of these devices by humans. Essentially, the techniques used 10 years ago are still used for inspection in production lines. Much of the inspection is done by humans whose performance?not surprisingly?is generally inadequate and variable. The human visual system is adapted to perform in a world of variety and change; the inspection process, on the other hand, requires observing the same type of image repeatedly to detect anomalies. This requirement can often be met successfully by automation.